"The Chinese side... is deeply worried about the severe consequences that such actions might bring," foreign ministry spokesman Lin Jian said.

"The Chinese side calls on relevant parties to take actions that promote regional peace and stability and to avoid further escalation of tensions," Lin said.

Israel pounded Iran in a series of air raids on Friday, striking 100 targets and killing the armed forces' chief of staff, the head of Iran's Revolutionary Guards and top nuclear scientists.

Iran's supreme leader Ayatollah Ali Khamenei warned Israel it faced a "bitter and painful" fate over the attacks.

The Israeli military said later that Iran launched 100 drones towards Israel in response and that its air defences were intercepting them outside Israeli territory.

China enjoys close ties with Iran, being its largest commercial partner and the main buyer of its oil with Tehran still under crushing US sanctions.

On Friday, Lin said Beijing "opposes violations of Iran's sovereignty, security, and territorial integrity."

"We oppose escalating tensions and expanding conflicts," he said, adding: "The sudden escalation of the regional situation does not serve the interests of any party."

"The Chinese side is willing to play a constructive role in easing the situation," Lin added.